South Park Bridge

The new South Park Bridge. Photo by Andrew Pogue.

Waterway access

The Code of Federal Regulations is the current legislation guiding the South Park Bridge vessel opening schedule, which currently states that the bridge is prohibited from opening for vessel traffic between 6:30 a.m. – 8:30 a.m. and 3:30 p.m. – 5:30 p.m., Monday through Friday, except on Federal holidays. The Seattle Department of Transportation operates the South Park Bridge under contract for King County and can be reached at 206-549-2896.

About the new bridge

The new South Park Bridge on 14th Avenue S/16th Avenue S opened to traffic at 6 a.m. Monday,
June 30, 2014. With two piers capped by brick-surfaced control towers and a sweeping bascule design,
the new bridge recreates the look of its predecessor and returns a familiar silhouette to the lowrise
South Park skyline. The King County Department of Transportation managed the project.

The new bridge spans the Duwamish waterway, a short distance from where the old South Park
Bridge once stood. The structure is a bascule, or drawbridge, with two moveable leaves forming
the main span so the bridge can be opened for marine traffic below.

The main bridge piers in the river are concrete, supported by sunken concrete caisson
foundations. Both approach spans are made of precast concrete I-beam girders that support the
bridge deck. The bridge has four driving lanes, two bike lanes and two sidewalks.

The project also included:

intersection realignment, roadway
improvement and safety upgrades in the
South Park business area

a rain garden with natural water treatment

historic and art elements built into the new
structure

streetlights and bridge lighting

riverbank cleanup and plantings

utility relocation, and demolition of the
remaining portions of the old bridge

The rain garden

The rain garden area packs a lot of features into a small strip of right-of-way. The pocket park is
located on the footprint of the former South Park Bridge and provides much-needed access for
the community to reach the river. It naturally filters runoff from the south half of the bridge and
surrounding streets, lessening demand on Seattle's stormwater collection system. It also
preserves local history by featuring many salvaged parts from the old bridge and offers a view of
some of the art elements incorporated into the project under the 1% for Art program. Finally,
interpretive signs in the area offer information on the area's history, archeology, bridges, and
other topics of interest.

The old bridge

The old South Park Bridge was open from 1931 to 2010 and was an iconic feature of this
historic community. The bridge was closed to all traffic on June 30, 2010, due to severe
deterioration and earthquake vulnerability. The community and county leaders turned out in
huge numbers for the last crossing of the bridge and continued efforts to identify and seek
funding for a replacement bridge.

The community of South Park was tireless in its efforts to make sure the bridge and the
connections it provides were not forgotten. County Executive Dow Constantine was ultimately
successful in building a coalition of agencies to fund construction of a new bridge. U.S. Senator
Patty Murray and U.S. Representative Jim McDermott were also instrumental in the effort,
supporting the county's application to the U.S. Department of Transportation for a federal
stimulus grant.

Budget

Bridge fun facts

Just two 75 horsepower motors required to run under normal speeds and normal
operation—just a little more power than it takes to run a Prius.

Main pier on south side of the bridge was sunk 70 feet below the river bed and contains
more than 16 million pounds of concrete. The north pier was sunk half as much again
(110 feet) and contains more than 21 million pounds of concrete.

The new decking on the draw span is made up of lightweight concrete that is 22 percent
lighter than regular concrete.

750,000 feet of electrical wiring—the equivalent to 83 homes or enough to stretch from
South Park to Yakima.

Rain garden made up of a two-foot thick layer of specially mixed bio-retention soil that filters
runoff from the bridge as water drains through the soil. A perforated pipe at the bottom of the
garden collects the cleaner filtered water and sends it to the river.

The old bridge carried approximately 20,000 vehicles a day with 14 percent truck traffic.

14th Avenue S red brick road was removed, with the historic bricks being reused or
preserved in sidewalks, crosswalks and other areas of the new bridge.